Web Case Study--Airport Faces Storm Water Discharge Challenge
The Cincinnati/Northern Kentucky International Airport has bid to become the focal point for regional aviation for the central United States. The recent $100+ million expansion of the DHL Worldwide Express Cargo Facility at the Cincinnati/Northern Kentucky International Airport posed significant challenges in the area of treatment of storm water runoff.
The 1972 Amendments of the Clean Water Act prohibit the discharge of any pollutant to waters of the United States from a point source unless the discharge is authorized by a National Pollutant Discharge Elimination System (NPDES) permit. The NPDES permitting program is designed to track point sources, monitor the discharge of the pollutants from specific sources to surface waters, and require the implementation of the controls necessary to minimize the discharge of pollutants. The EPA requires facilities that engage in regulated industrial activities to obtain NPDES permits before discharging storm water. Airport de-icing and fueling facilities are specifically identified as industrial activities subject to the NPDES regulations.
This was a significant concern of URS Corp. of Tampa, FL, the engineering firm for the airport's new air cargo expansion project. The engineers selected the Highland Tank Model HTC "EZ Access" Oil/Water Separator designed for the treatment and discharge of contaminated storm water runoff in compliance with the facility's NPDES permit. Two 30,000-gallon, one 40,000-gallon, and two 50,000-gallon oil/water separators were installed by Matsuda, Inc., of Brooks, KY. These double-walled oil/water separators were supplied with special leak detection and oil level sensors and alarm/control panels.
The oil/water separators were required to meet the new Underwriter's Laboratories SU2215 approval for engineered oil/water separators rated at 10 ppm oil and grease. Currently, code enforcement officials consider UL-SU2215 certification as being the preeminent national consensus standard for oil/water separator construction and performance. UL-SU2215 establishes the design, construction and performance standards for oil/water separators.
To comply with OSHA's requirements on confined space entry into a vessel containing harmful fumes, Highland Tank's "EZ Access" oil/water separators were supplied. The "EZ Access" separator has large rectangular access chambers to allow for unrestricted access from above to the removable parallel corrugated plate and Petro-Screen coalescers contained within the separator for visual inspection, cleaning and maintenance.
Because of the large area for collection of the de-icing and transport fueling operations, and the required sloping of the piping (1/8" per foot typically), the separators had to be buried with the tops approximately 30 feet below grade level. The protected steel separators were specially designed for the extreme pressures from the weight of the overburden. Steel-reinforcing rings were welded to the steel shell for additional strength. The separators were protected with an internal HighCote lining and the Steel Tank Institute's approved ACT-100-U corrosion protection system.
With this project, the airport planners and designers made every effort to ensure that storm water discharge from the expanded facility poses no threat to water quality.